IBIS provides V-I curve, where data is presented as a table of current measurements, taken at a series of output voltages that covers a range of –Vcc to +2Vcc. According to the IBIS Voltage Convention, the voltage in the table for pullup and power clamp curves is:

Vtable = Vcc - Voutput

And, is therefore, the voltage across the pullup circuit referenced to Vcc and not to ground, by convention. At the same time, the pulldown curves are normally referenced to ground. The range –Vcc to +2Vcc is chosen because those are the limits of the voltage swings that can be seen on a transmission line with high reflection (high mismatch) coefficients when switching a driver from Vcc high state to 0 V low state.

So, let’s consider the V-I curve of “gpiohv_ds111_sr101_mio” model in file “21x21_imx6q_consmr_004.ibs”. In pulldown section - to estimate the IOL (in open drain, sink current) – current of ~50 mA can be gotten.

We do not provide separate DC hardware specs for i2C signals in our i.MX6 Datasheet(s), assuming common GPIO DC parameters for it. Values of load current in the Datasheet(s) relate to some typical configurations, in particular - in order to guarantee specified output voltages. For more accurate (application depended) estimations IBIS models should be applied. I looked at i.MX6 IBIS – it meets the mentioned NSP specs.

IBIS provides V-I curve, where data is presented as a table of current measurements, taken at a series of output voltages that covers a range of –Vcc to +2Vcc. According to the IBIS Voltage Convention, the voltage in the table for pullup and power clamp curves is:

Vtable = Vcc - Voutput

And, is therefore, the voltage across the pullup circuit referenced to Vcc and not to ground, by convention. At the same time, the pulldown curves are normally referenced to ground. The range –Vcc to +2Vcc is chosen because those are the limits of the voltage swings that can be seen on a transmission line with high reflection (high mismatch) coefficients when switching a driver from Vcc high state to 0 V low state.

So, let’s consider the V-I curve of “gpiohv_ds111_sr101_mio” model in file “21x21_imx6q_consmr_004.ibs”. In pulldown section - to estimate the IOL (in open drain, sink current) – current of ~50 mA can be gotten.